Patent GB-1335587-A (GB)
Title: Method and apparatus for placing a wrap around three sides of an article
IPC: B65B11/08
Filed: 1971-12-17
Abstract: 1335587 Wrapping machines BROOK-HIRST IGRANIC Ltd 17 Dec 1971 [17 Dec 1970] 58637/71 Heading B8C In a wrapping machine, the edges of a web 48 are guided vertically upwards so that the web blocks the path of movement of a stack of newspapers, and the leading edge of the web is held whilst the web guides are retracted, so that when the stack is conveyed against the web the latter is placed around the top, front, and bottom of the stack. The stack is conveyed by an input conveyer 16 and an output conveyer 18 which are separated by a cover-plate 50 slotted at 56. Driver rollers 62 project through the slot 56 to carry the stack between the conveyers 16, 18. The web 48 is withdrawn from a roll 50, mounted below the conveyer 18, by driven rollers 76 against which the web can be urged by idler rollers 66, and is guided up through the slot 56 by a curved guide 84. An arch structure 10 having uprights 110 and a top cross-member 112 is mounted astride the cover plate 58. A mounting plate 116 is secured to each upright 110 and pivotally supports a pneumatic ram 128, a bell crank lever 130, and a link 126. One arm of each bell crank lever 130 is connected to the piston of the ram 128 whilst the other arm, and the link 126, are connected to a pair of plates which co-operate to form a slot 136 for guiding one edge of the web. The lower part of each slot 136 is flared and lies directly above the slot 56 in the cover-plate 58. A U-shaped mounting member 150 is adjustably secured to the uprights 110 and co-operates with a connecting plate 152 to form a ring enveloping both uprights. A pressure plate 162 is fastened to the inner face of the connecting plate 152 and co-operates with a further plate 170 to form a web receiving slot. The inner face of the member 150 supports a pair of blocks 176 which rotatably support a shaft 178 carrying, at its ends, a pair of arms 182 supporting rollers 84 adapted to hold the web against the pressure plate 162. Between the arms 182, the shaft 178 supports a crank arm 186 attached to the piston of a ram 189. A flexible curtain 208 hangs from the member 150 and serves to fold the web on to the top of the stack. An L-section shield 210 covers each web guiding assembly. In operation, with the web extending across the cover-plate 58 and being held between the pressure plate 162 and the rollers 184, an incoming stack trips one finger LS1a of a limit switch (LS1, Fig. 12) to urge the idler rollers 66 against the driven rollers 76 to withdraw more web from the roll, this extra length of web being placed along the bottom of the stack as the stack pulls the top of the web from between the rollers 184 and the pressure plate 162, during which movement the top of the web is pulled past a roller 204 which prevents tearing by the plate 170. When the stack is clear of a second finger LS1b of the switch (LS1), the idler rollers 66 are retracted from the rollers 76 and a cutter blade 88 is operated to sever the web from the roll. On clearing the slot 56, the stack strikes the arm of a second switch LS2 to retract the cutter blade 88, and allow the rollers 184 to be retracted by rotation of the shaft 178 by the ram 189. At the same time web feeding is reinitiated and springs in the rams 128 extend the tracks 136. After an interval, web feeding is halted and the rams 128 are extended by compressed air to retract the tracks. The ram 189 is then vented to allow springs therein to urge the rollers 184 against the pressure plate.